Mechanisms of Twin-Roll Caster Tips Degradation

Blackening and degradationDegradation of twin roll caster (TRC) tipsTips can be observed at the leading edge closest to the caster roll shell and on the hot face of the tipTips in the regions in contact with aluminumAluminum after prolonged contact times. Although commonly observed, the exact mechanisms involved in the blackening reactions have never been researched and documented in depth. This paper details the analysis and investigations performed, provides insight into the reactions, and offers a comprehensive understanding of the mechanisms involved. It is shown that silica, from both the colloidal binder and aluminosilicateAluminosilicate fibers used in the tipTips manufacturing process, gets reduced by molten aluminumMolten aluminum via the formationFormation of corundum and spinel phases, while blackening at the leading edge, is the result of staining from the release agent applied on the roll shell burning in the vicinity of the tipTips.